Seat device

Abstract

A seat device that can reliably prevent a rotation operation of a seat by a seated person, in a long state where the back of the seat is along a wall. A rotation lock mechanism ( 60 ) that can restrain the rotation of a seat ( 1 ), a rotation operation unit ( 200 ) that performs a release operation of restraint by the rotation lock mechanism ( 60 ), and a rotation operation prevention mechanism ( 210 ) that disables the release operation in the rotation operation unit ( 200 ), when the seat ( 1 ) is in the long state are included. The rotation operation prevention mechanism ( 210 ) includes an engaging unit ( 211 ) provided in the leg stand ( 11 ), and an engaged unit ( 207 ) that is provided in the rotation operation unit ( 200 ) in the movable stand ( 20 ), and disables the release operation in the rotation operation unit ( 200 ) by being engaged with the engaging unit ( 211 ) when the seat ( 1 ) is in the long state.

What is claimed is: 
     
       1. A seat device that can convert a state of a seat, comprising:
 a rotation lock mechanism that restrain the seat at each of a plurality of rotation angles, the seat being rotatable about a rotation axis; 
 a rotation operation unit that performs a release operation that releases the seat from restraint by the rotation lock mechanism; and 
 a rotation operation prevention mechanism that disables the release operation of the rotation operation unit when the seat is in a specific state at one of the rotation angles, 
 the rotation operation prevention mechanism comprising: 
 an engaging unit provided on a fixed side of the seat; and 
 an engaged unit that is provided in the rotation operation unit on a movable side of the seat, and disables the release operation of the rotation operation unit by being engaged with the engaging unit when the seat is in the specific state, 
 the rotation operation unit is displaced between a using position at which the release operation is enabled, and a housing position at which the release operation is disabled, and 
 when the seat is in the specific state, the rotation operation prevention mechanism displaces the rotation operation unit from the normal position to the housing position, and restrains the rotation operation unit in the housing position by engaging the engaged portion with the engaging portion. 
 
     
     
       2. The seat device according to  claim 1 , further comprising:
 a rotation mechanism that rotates the seat about the rotation axis; and 
 a sliding mechanism that advances and retracts the seat together with the rotation mechanism from the fixed side, 
 wherein the rotation mechanism interlocks with the sliding mechanism to convert the state of the seat between a long state where a back of the seat is substantially parallel to and along a wall, and a cross state where the back of the seat is separated from the wall in a direction substantially orthogonal to the long state, and 
 the specific state of the seat corresponds to the long state. 
 
     
     
       3. The seat device according to  claim 2 , further comprising:
 a leg stand fixed on a floor surface on the fixed side of the seat; and 
 a movable stand on the movable side of the seat, the movable stand being supported by the leg stand via the sliding mechanism so as to be able to advance and retract, the seat being rotatably supported by the movable stand via the rotation mechanism, 
 wherein the engaging portion is provided in the leg stand, and 
 the rotation operation unit and the engaged portion are provided in the movable stand. 
 
     
     
       4. The seat device according to  claim 3 , wherein the rotation operation unit includes a pedal that is supported on a base end side being a rotation center, so as to be able to be swung between the using position at which the pedal protrudes forward on one end side of the movable stand, and the housing position at which the pedal is upwardly upright,
 the engaged portion is provided at a position eccentric from the rotation center of the pedal, and 
 while the pedal is normally maintained in the using position by biasing means, when the engaged portion is engaged with the engaging portion, the pedal is swung to be in the housing position against a biasing force of the biasing means, and is restrained in the housing position.